Online resources such as Internet Web pages provide opportunities for companies to market their products and services and to build brand awareness. These opportunities may be met when a company succeeds in getting information about its products and services posted on the Web pages. An example of such a Web page is one that displays search results returned as a result of a query submitted by a Web site visitor. Along with the displayed search results, the search results Web page also may display content segments that the company has produced to publicize its products and services. One typical mechanism for selecting which content segments should be served with the search results Web page involves an auction in which companies submit bids for the placement of their content segments.